A248841 Number of length n arrays x(i), i=1..n with x(i) in 0..i and no value appearing more than 7 times.

2, 6, 24, 120, 720, 5040, 40320, 362878, 3628706, 39913932, 478928016, 6225275778, 87138262602, 1306763837486, 20901947961712, 355203011199460, 6390875986594862, 121365402664456728, 2425912530967520904

Offset: 1

Author

R. H. Hardin, Oct 15 2014

Keywords

• nonn

Comments

Column 7 of A248842

Examples

			Some solutions for n=6
..1....0....1....1....0....1....1....0....1....1....1....0....0....1....0....0
..0....2....2....2....1....1....1....2....0....1....0....1....0....1....2....0
..1....2....3....3....0....3....1....2....2....3....1....3....0....2....3....0
..2....3....3....4....0....0....0....3....0....2....3....1....3....3....2....3
..0....1....1....0....4....1....4....2....3....4....1....2....0....3....1....5
..1....5....2....3....3....6....6....5....0....4....0....2....0....2....6....0
		

Links

• R. H. Hardin, Table of n, a(n) for n = 1..95